The present invention relates to a fuel adaptor for an internal combustion engine and, more particularly, to an adaptor, to facilitate engine operation with either of or both gasoline and an alternative fuel, such as LPG (liquid petroleum gas) or CNG (compressed natural gas),
Various fuel injector adaptors are known which facilitate adapting a gasoline injection engine so that it can be supplied selectively with gasoline and/or an alternative fuel, such as LPG or CNG, with no required change to the engine block of the engine. Examples of such adaptors are disclosed in U.S. Pat. Nos. 5,713,336 and 5,592,924. Typically, such injector adaptors receive and seat separate gasoline and alternative fuel injection devices. The adaptors are mounted in apertures within the intake manifold of the engine (or, alternatively, the intake port of each combustion chamber in the engine) for communication therewith, in lieu of the gasoline injection devices originally provided with the engine.
In some cases, it is necessary or preferred to seat the gasoline fuel injector in the adaptor so that the injector remains at or near its original position within the engine. An example of this manner of seating a gasoline fuel injector is disclosed in FIG. 6B of U.S. Pat. No. 5,713,336. To effect this seating arrangement in the adaptor, the discharge nozzle of the gasoline fuel injector must be spaced from the inner side walls of the adaptor to provide a passage for flowing the alternative fuel from its corresponding injection device, through an adaptor outlet hole, and to the engine. Because the discharge nozzle is spaced from the inner side walls of the adaptor to thereby permit flow of the alternative fuel in the interstitial space, there is opportunity for lateral movement of the discharge nozzle in response to engine vibrations resulting from normal operation. If that happens, the discharge nozzle may become oriented such that injected fuel impinges on surrounding structures, thereby losing speed, before entering the intake manifold (or intake port, as the case may be). In such circumstances, fuel is not properly delivered to the combustion chamber, thereby compromising engine performance.
To overcome the aforesaid disadvantages of prior art adaptors, an adaptor for adapting a seat of an engine capable of using a first fuel and having a seat for receiving a first fuel injector means with a discharge nozzle for flowing the first fuel is provided. Such adaptor comprises a body having a bore with side walls for receiving the first fuel injector means, a plurality of spaced apart protuberances extending from the sidewalls thereof for limiting movement of the discharge nozzle, an inlet for receiving a second fuel, and an adaptor hole for communicating with the discharge nozzle and the inlet, the adaptor hole being formed through a portion of the body which is to be fitted within the seat of the engine originally provided for receiving the first fuel injector means. The protuberances can extend radially from the side walls. The protuberances can also extend from a region of the side walls opposite the discharge nozzle of the fuel injector means. To this end, the protuberances limit lateral movement of the discharge nozzle. The protuberances can also surround the discharge nozzle. The discharge nozzle can have an exterior surface defining a perimeter, and each of the protuberances can be radially spaced from the perimeter at spaced intervals around the perimeter. The fuel injector means can be seated in the adaptor such that the discharge nozzle is disposed below the inlet associated with the second fuel, and the protuberances are spaced apart for flowing the second fuel from the inlet to the adaptor outlet hole. The discharge nozzle has an outlet and the outlet is aligned with the adaptor outlet hole. Each of the at least one combustion chamber has an intake port and the adaptor is mounted on the intake port for communication of the adaptor outlet hole with the intake port. Alternatively, the engine can have an intake manifold and the adaptor is mounted on the intake manifold for communication of the adaptor outlet hole with the intake manifold.
The present invention also provides an engine capable of using a first fuel having at least one combustion chamber, and adapted to use both the first fuel and a second fuel, comprising a first fuel injector means, associated with each of the at least one combustion chamber, the fuel injector having a discharge nozzle at one end for flowing the first fuel to a corresponding one of the at least one combustion chamber, an adaptor, associated with each of the at least one combustion chamber, for adapting a seat of the engine originally provided for receiving the first fuel injector means, comprising a body having a bore with side walls for receiving and seating the fuel injector means, a plurality of spaced apart protuberances extending from the side walls for limiting movement of the discharge nozzle of the first fuel injector means, an inlet for receiving the second fuel, and an adaptor outlet hole, communicating with the discharge nozzle and the inlet, the adaptor outlet hole being formed through a portion of the body which is to be fitted within a seat of the engine originally provided for receiving the first fuel injector means.
By having protuberances extending from the side walls of the adaptor, the discharge nozzle of a first fuel injector can be restricted, while permitting flow of a second fuel from a second fuel injector in spaces between the protuberances. This is particularly advantageous where it is necessary to position the first fuel injector such that its discharge nozzle is not spaced from the adaptor outlet while requiring that passages remain for flowing the second fuel from the second fuel injector.